Updated

Authorities say police have arrested more than two dozen people as they cleared squatters from a Berlin building that was occupied for two decades.

Berlin's state interior minister, Ehrhart Koerting, said several officers sustained light injuries when fire extinguishers were sprayed at them during Wednesday's operation against squatters and their supporters elsewhere.

The house in the former East Berlin was occupied as Germany was reunited in 1990. Residents were given rental contracts at one stage but those were later terminated when private investors bought the building.

Koerting said nine people inside the house were detained. The operation was complicated by damage inside, including partially removed staircase.